JP4207981B2 - Information processing apparatus, information processing method, program, and recording medium - Google Patents

Description

  The present invention relates to an information processing device, an information processing method, a program, and a recording medium, and particularly to an information processing device, an information processing method, a program, and a recording medium that are suitable for editing an encoded stream.

  In an MPEG stream that is encoded using correlation between frames, when editing by connecting different streams, only a connected portion of each stream, that is, only a GOP including an edit point is used by using a plurality of decoders. After decoding, switching and connecting the decoded baseband image data output from each decoder at a desired position, and then re-encoding, the editing process to connect different streams can be executed There has been a technique that has been made (for example, Patent Document 1).

JP-A-10-98713

  That is, as shown in FIG. 1, a clip 2 that is a part of the first stream that is the material of the edited image and a clip 4 that is a part of the second stream that is the material of the edited image When it is desired to connect, when a frame necessary for decoding each frame of the clip 2 exists in the portion of the stream 1 that is not displayed, the decoder A has a frame group 1 ′ necessary for reference included in the stream 1 and When the clip 2 is input and decoded, input to the selector, and a frame necessary for decoding each frame of the clip 4 is present in the portion of the stream 3 that is not displayed, the decoder B receives the stream Frame group 3 'and clip 4 necessary for reference included in 3 are input and decoded and input to the selector. That. The selector switches the output between the baseband image data of the portion of the clip 2 that is a part of the first stream that is the material of the edited image and the part of the second stream that is the material of the edited image. The baseband image data of a certain clip 4 part is connected, supplied to an encoder, re-encoded and output.

  However, in the above-described conventional technique, since it takes time to re-encode after once decoding the GOP including the connection portion, it is necessary to change the joints by editing or the like to check the joint positions. It is not suitable.

  Further, in the conventional technique, it is necessary to prepare a plurality of decoders, assign one decoder to one stream as a video material, and switch the output by an external selector or the like. That is, in the conventional technique, it is necessary to prepare a plurality of decoders, and it is necessary to control the stream input to each of those decoders and the output timing of baseband image data after decoding. It was done. In particular, when performing random playback such as scrub playback, a picture that should not be displayed may be displayed unless the selector is controlled in accordance with the output of each of the plurality of decoders. For this reason, it is necessary to perform a complicated process of controlling the selector in accordance with the output timing of the baseband image data to be displayed by each decoder. After the user inputs an operation for specifying the connection position, the connection stream is reproduced and output. The response until is delayed.

  The present invention has been made in view of such a situation, and makes it possible to reproduce and output a reproduced image when an encoded stream is connected at a desired editing point without complicated control.

An information processing apparatus according to an aspect of the present invention is an information processing apparatus that performs control so that a first encoded stream and a second encoded stream are output in a connected state, the first encoding stream Decoding the encoded stream stored in the operation input acquisition means for acquiring the operation input indicating the playback range of the stream and the second encoded stream; and the storage means for storing the encoded stream Corresponding to the decoding means for generating image data, the first encoded stream and the second encoded stream in the range corresponding to the operation input acquired by the operation input acquisition means, and the operation input range of the first encoded stream and the coded stream necessary for decoding the second encoded stream, transferred to the storage means Controls, the first encoded stream and the second encoded stream to determine a transfer unit for transferring to said storing means, commands the timing for outputting the image data decoded by said decoding means command to When the picture of the image data whose output is commanded by the means is included in a B picture that is decoded with reference to a picture included in a second GOP different from the first GOP in which the picture is included, Of the first GOP, a B picture to be decoded with reference to a picture included in the second GOP, a reference picture necessary for decoding the B picture, and the second GOP a transfer control means for determining a transfer unit for transferring said storage means, out of the image data instructed by said instructing means The transfer timing is predicted so that the timing command is predicted, and the first encoded stream and the second encoded stream are transferred to the storage means prior to the output timing command of the image data. A transfer timing control means for controlling, and a reference picture to be referred to when decoding a picture to be decoded among the first coded stream and the second coded stream stored in the storage means is given priority. Decoding control means for controlling the decoding of the decoding means so as to decode.

The transfer control means controls the first encoded stream and the second encoded stream to be transferred to the storage means as transfer data in a predetermined transfer unit, and the transfer timing control means When the number of pictures to be displayed is less than or equal to a predetermined number of pictures among the transfer data whose transfer to the storage means is controlled, the next transfer data can be controlled to be transferred to the storage means .

The first encoded stream and the second encoded stream have a GOP structure including a B picture, and the transfer control means includes a picture of the image data whose output is instructed by the instruction means. When neither the first GOP nor the second GOP has been transferred to the holding unit, the first GOP is decoded with reference to a picture included in the second GOP of the first GOP. A B picture, a reference picture necessary for decoding the B picture, and the second GOP can be determined as a transfer unit to be transferred to the storage means .

According to the operation input acquired by the operation input acquisition means, control information generation means for generating control information indicating a range for reproducing the first encoded stream and the second encoded stream is further provided . can do.

The first encoded stream and the second encoded stream have a GOP structure, and the transfer control means converts the first encoded stream and the second encoded stream into GOP units. Can be controlled to transfer .

The first encoded stream and the second encoded stream may be streams encoded according to the MPEG standard .

An information processing method and a program according to one aspect of the present invention are an information processing method for an information processing apparatus that performs control so that a first encoded stream and a second encoded stream are output in a connected state. An operation input indicating a range to be reproduced of the first encoded stream and the second encoded stream is acquired, and the first encoded stream in the range corresponding to the acquired operation input and the A second encoded stream, and an encoded stream necessary for decoding the first encoded stream and the second encoded stream in a range corresponding to the operation input are stored in the encoded stream. It controls to transfer to the storage unit, the transfer unit for transferring the first encoded stream and the second coded stream to the storage means And a picture of the image data for which the timing to output the image data obtained by decoding the encoded stream stored in the storage means is different from the first GOP including the picture. A B picture decoded with reference to a picture included in the second GOP of the first GOP when included in a B picture decoded with reference to a picture included in the GOP; The reference picture necessary for decoding the B picture and the second GOP are determined as transfer units to be transferred to the storage means, and the encoded stream stored in the storage means is decoded. The output timing of the image data is predicted, and the output timing of the image data is predicted. The transfer timing is controlled so that the first encoded stream and the second encoded stream are transferred to the storage means prior to the storage command, and the storage is stored in the storage means. Control is performed so as to preferentially decode a reference picture to be referred to when decoding a decoding target picture out of the first encoded stream and the second encoded stream.

In one aspect of the present invention, an operation input indicating a range to be reproduced of the first encoded stream and the second encoded stream is acquired, and the first code is based on the acquired operation input. The storage means stores the encoded stream and the second encoded stream, and the encoded stream necessary for decoding the first encoded stream and the second encoded stream in the range corresponding to the operation input. Image data obtained by decoding the encoded stream stored in the storage unit, in which a transfer unit for transferring the first encoded stream and the second encoded stream to the storage unit is determined. A picture included in a second GOP different from the first GOP in which the picture of the image data instructed to output A B picture decoded with reference to a picture, and a B picture decoded with reference to a picture contained in the second GOP of the first GOP, and the B picture The reference picture necessary for this purpose and the second GOP are determined as transfer units to be transferred to the storage means, and the timing for outputting the decoded image data of the encoded stream is instructed. Then, the transfer timing is controlled so that the output timing command of the image data is predicted, and the first encoded stream and the second encoded stream are transferred prior to the output timing command of the image data. In the stored first encoded stream and second encoded stream, the reference picture that is referred to when decoding the decoding target picture is preferentially decoded.

  The network is a mechanism in which at least two devices are connected and information can be transmitted from one device to another device. The devices that communicate via the network may be independent devices, or may be internal blocks that constitute one device.

  The communication is not only wireless communication and wired communication, but also communication in which wireless communication and wired communication are mixed, that is, wireless communication is performed in a certain section and wired communication is performed in another section. May be. Further, communication from one device to another device may be performed by wired communication, and communication from another device to one device may be performed by wireless communication.

  The playback device may be an independent device, or may be a block that performs playback processing of the editing device or the recording / playback device.

  As described above, according to one aspect of the present invention, decoded data can be output. In particular, based on a user operation input, the first encoded stream and the second encoded stream can be output. Since the data including at least the encoded stream of the range to be reproduced and output and the encoded stream necessary for decoding these are supplied to the decoder, the editing process can be performed by one decoder. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a block diagram illustrating a hardware configuration of the playback device 1.

  A CPU (Central Processing Unit) 11 is connected to the north bridge 12 and controls processing such as reading of data stored in an HDD (Hard disk Drive) 16, scheduling of decoding executed by the CPU 20, decoding In addition, a command for instructing start, change, or end of processing such as display output control is generated and output. The north bridge 12 is connected to a PCI (Peripheral Component Interconnect / Interface) bus 14. For example, under the control of the CPU 11, the north bridge 12 receives supply of data stored in the HDD 16 via the south bridge 15 and receives the PCI bus. 14, and supplied to the memory 18 via the PCI bridge 17. The north bridge 12 is also connected to the memory 13, and exchanges data necessary for the processing of the CPU 11.

  The memory 13 is a storage memory that can store data necessary for processing executed by the CPU 11 and that can be accessed at high speed, such as DDR (Double Data Rate). The south bridge 15 controls writing and reading of data in the HDD 16. The HDD 16 stores compressed and encoded stream data.

  The PCI bridge 17 includes a command buffer 31 and a result buffer 32 therein, and is connected to a memory 18 that buffers stream data read from the HDD 16 under the control of the CPU 11. The PCI bridge 17 can supply stream data read from the HDD 16 based on the control of the CPU 11 to the memory 18 and store the stream data, and stream data stored in the memory 18 based on the control of the CPU 20. Is supplied to the memory 22 connected to the decoder 23. The PCI bridge 17 controls transmission / reception of a control signal corresponding to a command or a result via the PCI bus 14 or the control bus 19.

  The command buffer 31 receives commands written from the CPU 11 via the north bridge 12 and the PCI bus 14, and reads written commands from the CPU 20 via the control bus 19. The result buffer 32 receives a result written to the command by the CPU 20 via the control bus 19 and reads the written result from the CPU 11 via the north bridge 12 and the PCI bus 14. ing.

  The memory 18 stores compression-encoded stream data read by the HDD 16 based on the control of the PCI bridge 17 and is configured by, for example, SDRAM (Synchronous Dynamic Random Access Memory). .

  The CPU 20 reads a command written in the command buffer 31 of the PCI bridge 17 by the CPU 11 via the control bus 19, and controls processing executed by the PCI bridge 17, the memory 22, and the decoder 23 according to this command. . The memory 21 stores data necessary for the processing of the CPU 20.

  The decoder 23 decodes the supplied compressed and encoded stream data based on the control of the CPU 20 and outputs an uncompressed video signal. The decoder 23 can decode one frame in a time sufficiently shorter than the display time for displaying one frame (for example, about 1/4 or 1/3 of the time for displaying one frame). A memory 22 is connected to the decoder 23. The memory 22 can hold the compressed and encoded stream data supplied from the PCI bridge 17 or the uncompressed video signal decoded by the decoder 23. The decoder 23 may be provided as an independent device that is not included in the playback device 1.

  2 may be configured as a single device or may be configured by a plurality of devices. For example, in the playback device 1 of FIG. 2, the CPU 11, the north bridge 12, the memory 13, the south bridge 15, and the HDD 16 are part of the configuration of the personal computer. An expansion card such as a card or an expansion board is provided with the functions of the PCI bus 14, the PCI bridge 17, the memory 18, the control bus 19, the CPU 20, the memory 21, the memory 22, and the decoder 23, and the personal computer has the expansion card. May be attached to function as the playback apparatus 1. Further, these may be further divided into a plurality of devices to constitute the playback device 1.

  Next, the operation of the playback device 1 will be described.

  The HDD 16 stores compressed video data compressed by the MPEG Long GOP method.

  Only a part of a series of continuous images is cut out, and that part is used as a clip. Collecting a plurality of such clips and reproducing them as one continuous video is called clip reproduction.

  That is, as shown in FIG. 3, a clip 2 that is a part of the first stream that is the material of the edited image and a clip 4 that is a part of the second stream that is the material of the edited image If it is desired to connect, when the frame necessary for decoding each frame of the clip 2 is present in the non-displayed portion 1 (not included in the clip 2) of the first stream, the decoder 23 is required for reference. A frame group 1 ′ and a clip 2 are inputted and decoded, and a frame necessary for decoding each frame of the clip 4 is not displayed in the second stream (not included in the clip 4). 3, the decoder 23 receives and decodes the frame group 3 ′ and the clip 4 necessary for reference. Then, the decoder 23 performs baseband image data of a part of the clip 2 that is a part of the first stream and a baseband of a part of the clip 4 that is a part of the second stream that is the material of the edited image. The image data can be connected and output.

  At that time, there is a frame (that is, the frame group 1 ′ and the frame group 3 ′ in FIG. 3) that is not output but is necessary to be decoded depending on the break of the clip.

  As shown in FIG. 4, when a gap between the B9 picture and the B10 picture in a GOP in the stream A is a clip break and a clip up to the B9 picture is a clip A, B9 of the final GOP of the clip A In order to decode a picture, a P11 picture not included in clip A is required. When the gap between the GOP in the stream B and the next GOP is a clip break and the B0 picture after the GOP head is the clip B, the B0 picture and B1 picture of the head GOP of the clip B are decoded. In order to do this, all I pictures and P pictures of the previous GOP that are not included in clip B are required. That is, the maximum number of frames that must be decoded but not displayed in order to create a reference image of the frame to be displayed is six.

  The CPU 11 controls the south bridge 15 via the north bridge 12, and based on the operation input indicating the stream used in clip reproduction and the reproduction range in clip reproduction supplied from the operation input unit (not shown). A predetermined portion of a plurality of compressed and encoded stream data is read from the HDD 16 and supplied to the memory 18 via the north bridge 12, the PCI bus 14, and the PCI bridge 17, and stored. GOP transfer completion command indicating completion of data transfer to the memory 18, an output range designation command which is a command indicating a displayed range of the transferred GOP, that is, a frame range displayed in clip playback, playback speed Information indicating (including information indicating playback direction), decoding start Command to command, or the like command for instructing the start of the display, via the north bridge 12 and the PCI bus 14 and written into the command buffer 31 of the PCI bridge 17.

  The CPU 20 determines a schedule for decoding and outputting (displaying) the compressed and encoded stream data based on the command from the CPU 11 written in the command buffer 31 of the PCI bridge 17. Specifically, the CPU 20 transfers the compression-encoded stream data from the memory 18 to the memory 22, the input timing of the compression-encoded stream data from the memory 22 to the decoder 23, and the decoding for each frame. Timing, setting of the bank position of the reference image, allocation of bank memory at the time of decoding, and output of the decoded picture, that is, display timing is determined.

  Then, the CPU 20 controls the PCI bridge 17 to supply the compressed and encoded stream data stored in the memory 18 to the memory 22 based on the determined schedule, and to supply the data to the decoder 23.

  The CPU 20 controls the decoder 23 to decode the compressed and encoded data supplied via the memory 22. The decoder 23 decodes the supplied compressed and encoded stream data to generate and output non-compressed baseband image data.

  Specifically, the CPU 20 causes the decoder 23 to preferentially decode the I picture and P picture of the GOP supplied to the memory 22, and accumulates the obtained uncompressed baseband image data in the memory 22. Take control. Since the decoder 23 can decode one frame in a time sufficiently shorter than the display time for which one frame is displayed, it is stored in the memory 22 while the process for decoding the displayed frame is not performed. Since the uncompressed baseband image data obtained by preferentially decoding the I picture and P picture of the GOP being stored in the memory 22, when the display command is transmitted from the CPU 11, the stored I picture and By outputting baseband image data corresponding to a P picture or using these as reference images, decoding processing can be performed at high speed. That is, when a display command for a certain frame is supplied from the CPU 11, if there is uncompressed baseband image data to be displayed in the memory 22, it is output. If not, it is appropriately stored in the memory 22. The stored non-compressed baseband image data is used as a reference image, the displayed frame is decoded, and uncompressed baseband image data is generated and output. Note that all I and P pictures included in the GOP may be preferentially decoded, but only some of the I and P pictures included in the GOP are preferentially decoded. You may make it do.

  In the decoder 23, based on the control of the CPU 20, the I picture and the P picture are preferentially decoded, and a clip reproduction for collecting a plurality of clips and reproducing them as one continuous video is performed by the decoder 23. This is realized by controlling an internal selector 23. The detailed configuration and operation of the decoder 23 will be described later with reference to FIGS.

  Next, functions of the CPU 11 and the CPU 20 will be described with reference to the functional block diagram of FIG.

  The CPU 11 includes an operation input acquisition unit 51, a transfer GOP determination unit 52, a GOP transfer timing control unit 53, an output range information setting unit 54, a register 55, a transfer completion command transmission unit 56, a display command transmission unit 57, and a result acquisition unit. 58 including functions.

  The operation input acquisition unit 51 acquires a user operation input supplied from an operation input unit (not shown) via the south bridge 15 and the north bridge 12, and transfers information indicating the user operation input to the transfer GOP as necessary. The data is supplied to the determination unit 52, the GOP transfer timing control unit 53, or the output range information setting unit 54.

  The transfer GOP determination unit 52 obtains frames to be reproduced and output in a clip composed of a plurality of streams based on the user's operation input supplied from the operation input acquisition unit 51, and is necessary for decoding those frames. A frame is obtained, a frame display order is predicted and scheduled, a GOP to be transferred to the memory 18 is determined, a GOP transfer timing control unit 53 and an output range information setting unit 54 are notified, and a stream stored in the HDD 16 Controls reading and transfer of GOP to be transferred from.

  As described above, the transfer of frame data is basically performed in units of GOPs. However, in a clip stream composed of a plurality of clips obtained by cutting out a plurality of streams at arbitrary positions, the beginning and end of each clip are transferred. The GOP does not necessarily include all of one GOP in the editing material stream. In addition, as described with reference to FIG. 4, in order to decode the frames included in the first and last GOPs of the respective clips, a frame that is not displayed may have to be supplied to the decoder 23. For example, if the first or last GOP of each clip does not include all 1 GOPs in the editing material stream, all 1 GOPs in the editing material stream may be transferred, but only necessary portions are transferred. You may do it. Also, for example, when the first GOP of the clip includes the two B pictures at the beginning of the MPEG Long GOP in the editing material stream, one of the B pictures is not included in order to decode these B pictures. It is necessary to supply the previous GOP to the decoder 23. In such a case, the transfer GOP determination unit 52 determines a GOP to be transferred to the memory 18 so that the GOP that is not included in the clip is supplied to the decoder 23.

  As described above, the frame data is basically transferred in units of GOPs, but the first frame displayed in scrub playback or the first frame of the clip is the first B0 and B1 of the GOP. In this case, as described with reference to FIG. 4, an exception process is required to refer to the previous GOP frame.

  In particular, when playback frames are not continuous due to high-speed playback, etc., if transfer is performed completely in GOP units, for the GOP (n) including the first frame displayed in scrub playback or the first frame of the clip, It is necessary to perform transfer for 2 GOPs by adding the previous GOP (n-1). However, in scrub playback, the playback position frequently moves at high speed, and the next frame to be displayed is likely to be a frame included in a GOP other than GOP (n). In this case, if all GOP (n) data is transferred, the transfer data is wasted.

  Therefore, the transfer GOP determination unit 52, as an exception process, when the displayed frame is B0, B1 at the head of the GOP, the transfer GOP determination unit 52 displays the GOP (n−1), which is the GOP before the GOP with the frame to be displayed. The data transfer is controlled so that the frame is transferred in a form in which IOP, B0, and B1 of GOP (n), which is a GOP with a frame to be transferred. After that, when normal playback is instructed and display of frames included in GOP (n) is instructed, even if GOP (n) is transferred as usual, the redundant part of data transfer Is only I2, B0, B1, and the control is not complicated. This reduces data transfer waste and improves data transfer efficiency.

  The GOP transfer timing control unit 53 manages the GOP stored in the memory 18 by using various control queues provided in the register 55 as necessary, thereby transferring the GOP to the memory 18. Control timing.

  That is, as described above, frame data is basically transferred in units of GOPs. However, when a GOP including a frame is transferred when a display instruction for a frame is issued, the frame display is not performed. Response from command to display becomes very bad. Therefore, the GOP transfer timing control unit 53 predicts the frame to be displayed, and transfers the GOP data prior to the display command. As a result, the decoder 23 can decode the transferred GOP I picture and P picture in advance and store them in the memory 22.

  In addition, since the first and last GOPs of each clip do not necessarily include all of the 1 GOP in the editing material stream, if the transfer is a short GOP with a small number of frames, or In the case of a GOP with a small number of display frames even if the number of frames included in the transferred GOP is large, the display may not be in time unless the transfer of the next GOP is accelerated. Therefore, the GOP transfer timing control unit 53 controls the GOP transfer timing in consideration of the number of display frames included in the transferred GOP. Details of the transfer timing control will be described later.

  The output range information setting unit 54 determines the range to be displayed and output among the GOPs whose transfer has been determined by the transfer GOP determination unit 52, generates output range information, and after the transfer of the corresponding GOP is completed, Before the transfer completion command is supplied, the supply of the output range designation command to the command buffer 31 is controlled.

  That is, as described above, transfer of frame data is basically performed in units of GOPs. However, the first and last GOPs of each clip do not always include all 1 GOPs in the stream of editing material. In addition, when a GOP including a frame referred to for decoding of a frame included in the clip is transferred, there is a possibility that the frame of the GOP is not displayed at all. The output range information setting unit 54 determines a range to be displayed and output among the GOPs whose transfer is determined by the transfer GOP determination unit 52, generates an output range specification command as output range information, and sends it together with the transfer completion command , To be transmitted to the command buffer 31.

  The register 55 includes various queues used by the GOP transfer timing control unit 53 to control the GOP transfer timing, and holds various parameters necessary for processing.

  The transfer completion command sending unit 56 sends a transfer completion command to the command buffer 31 of the PCI bridge via the north bridge 12 and the PCI bus 14. Details of the transfer completion command transmission timing control will be described later.

  The display command sending unit 57 sends a display command to the command buffer 31 of the PCI bridge via the north bridge 12 and the PCI bus 14. Details of display command transmission timing control will be described later.

  The result acquisition unit 58 acquires the result for the command from the result buffer 32 of the PCI bridge via the north bridge 12 and the PCI bus 14.

  The CPU 20 has functions including a command acquisition unit 71, an inter-memory transfer control unit 72, a decode schedule processing unit 73, a decode control unit 74, a register 75, and a result sending unit 76.

  The command acquisition unit 71 sends commands sent from the output range information setting unit 54, transfer completion command sending unit 56, or display command sending unit 57 of the CPU 11 and held in the command buffer 31 of the PCI bridge 17 to the control bus. 19 to obtain.

  The inter-memory transfer control unit 72 controls transfer of each GOP transferred to the memory 18 to the memory 22 based on the transfer completion command and the display command acquired by the command acquisition unit 71.

  The decode schedule processing unit 73 controls the transfer to the memory 22 by the inter-memory transfer control unit 72 based on the output range designation command, the transfer completion command, and the display command acquired by the command acquisition unit 71, respectively. The decoding schedule of the frame included in the GOP is determined. The decode schedule processing unit 73 uses a time during which the decoding process necessary for display is not performed so that the I picture and the P picture of the frames held in the memory 22 are preferentially decoded. Schedule the decoding. It should be noted that all I pictures and P pictures may be preferentially decoded, or at least some of them may be decoded. Further, the decode schedule processing unit 73 uses the I picture and the P picture that have been decoded in advance and stored in the memory 22 so that the baseband image data of the frame instructed to be displayed is quickly output. , Do a decoding schedule.

  The decode control unit 74 controls the decoding processing by the decoder 23 based on the decoding schedule by the decoding schedule processing unit 73.

  The register 75 includes various control queues for the inter-memory transfer control unit 72 to manage GOPs supplied to the respective memories and decoders, and holds various parameters necessary for processing.

  The result sending unit 76 sends the result for the transfer completion command and the display command acquired by the command acquiring unit 71 to the result buffer 32 of the PCI bridge 17 via the control bus 19.

  In the playback device 1, instead of assigning a plurality of clips to a plurality of decoders, frames included in the plurality of clips and frames necessary for decoding them are supplied to the decoder 23, and the I picture and P By decoding a picture, clip playback can be realized with a single decoder, and clip-stream playback, scrub playback, and playback in the forward and reverse directions in a short interval. It is possible to perform transient reproduction that is commanded continuously.

  By having such a configuration, it is not necessary to have selectors at the input stage and output stage of the decoder and the control is simplified as compared with the conventional case where a plurality of decoders are used.

  Further, in this way, the playback apparatus 1 decodes at least a part of the I picture and P picture of the GOP data transferred in advance at a time when the decoding process for display is available. If the decoded baseband image data already exists when it is stored and a display command is received, the decoded baseband image data is output, and the displayed frame is not accumulated. In this case, a frame to be displayed can be decoded and output using the decoded baseband image data as a reference image as appropriate.

  FIG. 6 is a block diagram showing a more detailed configuration of the decoder 23.

  The input processing unit 151 stores the compression-encoded stream data supplied from the PCI bridge 17 in the stream buffer 22-1 and from the supplied stream data, the head address, the data size, and the picture header in units of pictures. Information, Q matrix, etc. are acquired and supplied to the stream information buffer 22-2.

  The stream buffer 22-1 is, for example, a predetermined storage area in the memory 22 of FIG. 2 configured by a storage memory such as SDRAM, and buffers the stream data supplied from the input processing unit 151. This is supplied to the selector 152. The stream buffer 22-1 can hold at least stream data of the same number of GOPs as the number of GOPs of I pictures and P pictures (also referred to as anchor frames) that can be held in a frame memory 22-3 described later. ing. Further, if the stream buffer 22-1 can hold the number of GOPs equal to or larger than the number of anchor frames that can be held in the frame memory 22-3, which will be described later, for example, the playback direction is reversed. If the playback start position is changed, there is a high possibility that it can be handled without supplying a new GOP to the stream buffer 22-1.

  The stream information buffer 22-2 is a predetermined storage area in the memory 22 of FIG. 2, and is supplied from the input processing unit 151 and includes information such as a head address in units of pictures, data size, picture header information, and Q matrix. For each picture.

  Based on the control signal supplied from the CPU 20, the decode controller 153 reads the address and stream information of each picture held in the stream buffer 22-1 from the stream information buffer 22-2, and processes each part of the decoder 23. To control.

  Specifically, the decode controller 153 is controlled by the CPU 20 based on a decode schedule set based on an output range designation command and the like, and by controlling the selector 152, each of the pictures supplied to the decode processing unit 154 is controlled. Controls picture decoding timing. Further, the decode controller 153 controls the selector 155 to control the storage position in the frame memory 22-3 of the baseband image signal obtained by decoding by the decode processing unit 154. Then, by controlling the selector 156, the decode controller 153 controls the baseband image signal supplied from the frame memory 22-3 as a reference image to the decode processing unit 154, that is, a P picture executed in the decode processing unit 154 or Controls supply of a reference picture in decoding of a B picture. The decode controller 153 is controlled based on the output schedule of the decoded image data set based on the output range designation command from the CPU 20, and the baseband image signal that the selector 157 reads from the frame memory 22-3 and outputs. By controlling the output of the decoded baseband image signal output for display or the like, that is, the display timing of the reproduced image.

  Based on the control of the decode controller 153, the selector 152 supplies the stream data stored in the stream buffer 22-1 to the decode processing unit 154 in units of pictures.

  The decode processing unit 154 decodes the MPEG video stream supplied from the selector 152 with reference to the reference image supplied from the selector 156 as necessary, and decodes the decoded baseband (uncompressed) image signal. This is supplied to the selector 155.

  Under the control of the decode controller 153, the selector 155 stores the recording position of the baseband image signal decoded and supplied by the decode processing unit 154 in the frame memory 22-3, that is, the baseband image signal. The bank position is determined, and the baseband image signal supplied from the decoding processing unit 154 is stored in a predetermined bank position of the frame memory 22-3. In other words, the decode controller 153 determines the bank position in the frame memory 22-3 of the baseband image signal obtained by decoding by the decode processing unit 154, and the baseband image signal is recorded at that position. Then, the selector 155 is controlled.

  The frame memory 22-3 is a predetermined storage area in the memory 22 of FIG. 2, and displays an I picture used as a reference image of other pictures, a reference bank storing a P picture, a B picture, and the like. The reference bank includes a reference bank for an anchor frame that is pre-decoded and held, and a reference for an anchor frame that is decoded according to the timing to be reproduced and output. There are separate banks. An example of the bank configuration in the frame memory 22-3 will be described later with reference to FIG.

  Under the control of the decoding controller 153, the selector 156 selects frame image data held in a bank designated as a forward reference image bank of the P picture in the frame memory 22-3, The frame image data held in the bank designated as the reference image bank in the forward direction and the backward direction (backward) are read out and supplied to the decoding processing unit 154.

  Under the control of the decode controller 153, the selector 157 reads out and outputs an output image of the frame image data held in the frame memory 22-3, that is, a bank of frames to be displayed.

  Next, the operation of the decoder 23 will be described. Here, as an example, a case where N15 and M3 MPEG LongGOP are decoded will be described.

  As shown in FIG. 7, each GOP supplied to the input processing unit 151 includes GOP header information in addition to the data of each picture composed of I, P, and B pictures. The GOP header information is given in advance to each GOP constituting the stream data held in the HDD 16, or GOP header information is generated by the processing of the CPU 20, read from the HDD 16, and read out by the decoder 23. Is provided to each GOP constituting the stream data supplied to.

  The GOP header information includes, for example, a GOP ID, the number of frames included in the GOP, and the number of anchor frames included in the GOP.

  The input processing unit 151 supplies the picture data to the stream buffer 22-1 and also sends the GOP header information and information such as the head address in units of pictures, data size, picture header information, and Q matrix to the stream information buffer 22-. 2 is supplied.

  The stream information buffer 22-2 holds the GOP header information and information such as the head address of each picture, data size, picture header information, and Q matrix.

  The decode controller 153 stores the GOP header information stored in the stream information buffer 22-2 and the information such as the head address of each picture, the data size, the picture header information, and the Q matrix. Decoding related information of each picture of the GOP is generated, and the stream buffer GOP queue shown in FIG. 8 configured by the header related information of the GOP and the decoding related information in the display order reordered in the display order is managed.

  The decoding related information is information necessary for decoding processing at the time of a picture output request. For example, the corresponding picture is a retained anchor frame, a non-retained anchor frame, or the first B picture of the GOP. Type information indicating whether the picture is a B picture other than the head of the GOP, a decoded image storage destination bank which is information indicating a storage destination of a decoded baseband image, and a reference image necessary for decoding the corresponding picture Of the forward reference picture index number indicating the forward reference picture, and the backward reference picture index number indicating the backward reference picture of the reference pictures necessary for decoding the corresponding picture, Consists of what is needed.

  In the stream buffer GOP queue, decoding related information for 1 GOP is managed as one data unit, and it is composed of FIFO (First in First Out) or new data is pushed. In this case, the information of the GOP that is farthest from the currently playing GOP is POP.

  In the decoder 23, all the anchor frames may be decoded in advance before the B picture, but here, it is assumed that only the anchor frames selected every several frames are decoded in advance before the B picture.

  Specifically, for example, in the decoder 23, as shown in FIG. 9, every other anchor frame in the GOP may be decoded in advance from the I picture. Hereinafter, an anchor frame that is decoded in advance and held in the bank is referred to as a retained anchor frame, and an anchor frame that is not decoded in advance, that is, not previously retained in the bank is referred to as a non-owned anchor frame.

  Specifically, for example, when a GOP with N: 15, M: 3, GOP ID 1 is input, and the GOP possession anchor information with GOP ID 1 uses the first bank used by the GOP possession anchor frame as 1. As shown in FIG. 10, information is accumulated in the stream buffer GOP queue.

  That is, GOP ID 1, number of frames 15 and number of anchor frames 5 are described in the GOP header information of the corresponding GOP. In the decoding related information, the picture type, decoded picture storage destination bank, forward reference picture index number, and backward reference picture index number of each picture reordered in the picture display order are described. Here, the picture type is not a classification of I, B, P, but is a retained anchor frame, a non-retained anchor frame, or one of the two B pictures at the head of the GOP ( The first B picture) or the B picture other than the first GOP of the GOP (non-first B picture). Then, the I picture of index 2, the P picture of index 8, and the P picture of index 14 are held anchor frames, and the P picture of index 5 and the P picture of index 11 are non-owned anchor frames.

  Only the retained anchor frame is determined in advance and the bank number is written in the decoded image storage destination bank. However, in the non-retained anchor frame and the B picture, it is not yet determined at the time when the decoding related information is generated. Since it is not, it becomes an indefinite value. The forward reference picture index number of the first B picture with index numbers 0 and 1 (the B picture with the previous GOP I picture or P picture as the reference picture) has the previous GOP in the stream buffer at the initial setting. Since it may not exist, it is not set at this time, and is set when the last I picture or P picture of the previous GOP is searched for at the time of decoding. Then, the forward reference picture index number and backward reference picture index number of the other B picture, and the forward reference picture index number of the P picture are set.

  Then, the decode controller 153 controls the decoding timing of each frame in the supplied stream data based on the decoding related information managed by the stream buffer GOP queue.

  That is, the decode controller 153 does not select all the anchor frames, but, for example, as described with reference to FIG. 9, every other anchor frame from the I picture or every other selected anchor frame is selected. Only the frame is set as the possessed anchor frame, and the selector 152 is controlled so that the decoding processing unit 154 decodes in advance during the idle time of the decoding process before the B picture is decoded.

  As described above, the decoding processing unit 154 decodes one frame with a sufficiently short time (for example, about 1/3 to 1/4 of the display time of one frame) with respect to the display time of one frame. Is possible. Accordingly, the decode controller 153 is configured so that the number of retained anchor frames that can be held in the frame memory 22-3 is decoded in advance in units of 1 GOP, supplied to a predetermined bank of the frame memory 22-3, and held. The selector 152, the selector 155, and the selector 156 are controlled.

  Every other anchor frame in the GOP is set as an owned anchor frame, and the frame memory 22-3 temporarily stores an area for temporarily storing baseband image data of X frames and display image data for two frames. FIG. 11 shows a bank configuration diagram when an area can be secured, that is, when a bank memory of X + 2 banks is secured.

  Of the banks corresponding to X + 2 frames in the frame memory 131-3, two banks are used as display-only banks for B pictures or non-owned anchor frames. Other banks, that is, banks for X frames are used for reference images. Of the reference image banks for X frames, one is used as a non-owned anchor bank for storing a baseband image of a non-owned anchor frame used as a reference image when the retained anchor frame is decoded in advance. The other one is used as a non-retained anchor bank for B picture display for storing a baseband image of a non-retained anchor frame used as a reference image when a displayed B picture is decoded. Then, the other X-2 frame banks are used as retained anchor banks for storing the decoded retained anchor frames.

  Specifically, when an I picture that is a retained anchor frame is decoded, the I picture is decoded alone and stored in the retained anchor bank. In addition, when a P picture that is a retained anchor frame is decoded, a non-retained anchor frame that is a previous anchor frame is a retained anchor frame that is stored in a retained anchor bank that is a previous anchor frame. The baseband image is decoded and stored in the non-retained anchor bank. With reference to this, the P picture that is the retained anchor frame is decoded and stored in the retained anchor bank.

  Then, when the display of any frame in the GOP in which the anchor frame is held in advance in the holding anchor bank is instructed, if the holding anchor frame is displayed, the holding anchor stored in the holding anchor bank The baseband image of the frame is read and displayed. If the non-owned anchor frame is displayed, the baseband image of the retained anchor frame stored in the retained anchor bank is used as a reference image, and the displayed non-owned anchor frame is decoded. It is stored in the display-only bank and displayed. If the B picture is displayed, the non-owned anchor frame is decoded with reference to the baseband image of the retained anchor frame stored in the retained anchor bank, which is the previous anchor frame. Stored in the non-owned anchor bank for B picture display, referenced with the baseband image of the retained anchor frame stored in the retained anchor bank, and the displayed B picture is decoded and stored in the display-only bank Displayed.

  That is, the retained anchor frame included in the GOP and the non-retained anchor frame necessary as a reference image for decoding the retained anchor frame are decoded in advance and stored in the frame memory 22-3. Non-retained anchor frames that are not required as a reference image for decoding retained anchor frames (for example, when the last anchor frame in GOP is a non-retained anchor frame) are displayed. Until then, the decoding process need not be executed.

  With reference to FIG. 12, the management of the frame memory 22-3 by the decode controller 153 will be described.

  As illustrated in FIG. 12, the decode controller 153 uses the retained anchor information and the GOP retained anchor information for a plurality of frames retained in the GOP retained anchor queue to control the timing of the retained anchor frame decoding process. . The retained anchor information is information necessary for creating a GOP retained anchor queue, and includes information on the first and last banks used, and the number of banks used. The GOP holding anchor queue is a bidirectional queue that can be pushed to both the head and tail, and is information about the holding anchor frame held between the head bank used and the tail bank described in the holding anchor information. A certain GOP possession anchor information is retained for each GOP. The GOP possession anchor information is information required when determining the bank storage location of the baseband image of the possession anchor frame of each GOP. The GOP possession anchor information includes the GOP ID of the corresponding GOP and the possession of the GOP. The first bank used by the anchor frame and the number of banks used by the anchor frame held by the GOP are included.

  The decode controller 153 uses the timing at which the displayed non-owned anchor frame or B picture is not decoded to schedule the decoding order so that the held anchor frame is preferentially decoded, and controls the selector 156. Then, the decoding processing unit 154 is caused to supply the retained anchor frame to execute the decoding process, and the decoding is performed while referring to the retained anchor information and the GOP retained anchor information for a plurality of frames retained in the GOP retained anchor queue. It is determined in which reference bank of the frame memory 22-3 the baseband image data of the retained anchor frame that has already been stored, and the selector 155 is controlled to determine a predetermined bank of the reference bank of the frame memory 22-3. Dedicated holding anchor in position Store frame baseband image data.

  When the retained anchor frame to be decoded in advance is an I picture, the selector 152 is controlled, the I picture is supplied to the decoding processing unit 154, and after decoding, the selector 155 is controlled to control the frame memory 22-3. Stored in one of the owned anchor banks.

  If the retained anchor frame to be decoded in advance is a P picture, the immediately preceding non-owned anchor frame is supplied to the decoding processing unit 154 and decoded, and then the selector 155 is controlled to control the frame memory. 22-3 stored in the non-owned anchor bank of the reference bank. Then, the selector 152 is controlled to supply the P picture that is the retained anchor frame to the decoding processing unit 154, and the selector 156 is controlled to refer to the baseband image data stored in the non-owned anchor bank. The P picture decoding process is executed, the selector 155 is controlled, and stored in one of the owned anchor banks of the reference banks of the frame memory 22-3.

  The decode controller 153 includes, among anchor frames included in the supplied GOP, a retained anchor frame that is previously subjected to decoding processing, and a non-retained anchor frame that is necessary as a reference image for decoding the retained anchor frame. The decoding schedule and the bank position of the reference bank after decoding are managed using an anchor frame decoding queue. That is, the decoding controller 153 determines whether each picture is a retained anchor frame or a non-retained anchor frame required as a reference image for decoding the retained anchor frame from the beginning of the GOP. In a picture to be decoded in advance, a bank position where the baseband image data after each decoding is held is set, and is pushed to the anchor frame decoding queue.

  With reference to FIG. 13 and FIG. 14, an example of specific processing for managing the owned anchor bank will be described. Here, a case where 10 banks can be used as possession anchor banks, that is, a case where 14 frames of baseband image data can be held in the frame memory 22-3 will be described.

  First, in the state of FIG. 13A, the baseband images of the anchor frames having GOP IDs 1, 2, and 3 decoded in advance are stored in banks 0 to 3 of the ten anchor banks in the frame memory 22-3. , Stored in banks 4 to 6 and banks 7 to 9. At this time, the retained anchor information and the GOP retained anchor queue managed by the decode controller 153 are in the state shown in FIG. 13B. That is, it is managed that the used first bank is 1, the last used bank is 9, and the number of used banks is 9, according to the retained anchor information, and the GOP ID anchor queue holds GOP ID1. The anchor bank uses three banks from bank 1, the anchor bank owned by GOP ID2 uses three banks from bank 4, and the anchor bank owned by GOP ID3 has three banks from bank 7 The use of is managed.

  Next, when the GOP ID 4 stream data with the anchor frame number 5 is supplied, the number of anchor frames held by the GOP with the GOP ID 4 is 3, and the only vacant bank is the bank 10, and the GOP ID Since all of the GOP possession anchor frames of 4 GOPs cannot be stored, it is necessary to delete any of the currently stored GOP possession anchor frames from the possession anchor bank.

  Therefore, the decode controller 153 POPs the GOP possession anchor information of GOP ID 1 which is the information related to the GOP farthest from GOP ID 4 out of the information currently retained in the GOP possession anchor queue from the GOP possession anchor queue. Push the ID 4 GOP holding anchor information to the tail of the GOP holding anchor queue.

  FIG. 14A shows the state of the ten anchor banks in the frame memory 22-3 at that time, and FIG. 14B shows the state of the possession anchor information and the GOP possession anchor queue. That is, among the ten owned anchor banks of the frame memory 22-3, banks 4 to 6 have GOP ID2 owned anchor frames, banks 7 to 9 have GOP ID3 owned anchor frames, and FIG. The stored anchor frames of GOP ID 4 that are newly supplied are stored in bank 10, bank 1, and bank 2 in the same manner as described above. And, it is managed by the possession anchor information that the first bank used is 4, the last bank used is 2, and the number of banks used is 9, and the GOP possession anchor queue holds GOP ID 2 The anchor bank uses three banks from bank 4, the GOP ID3 owned anchor bank uses three banks from bank 7, and the GOP ID4 owned anchor bank uses three banks from bank 10. The use of is managed.

  In this way, decoding by the decoder 23 is controlled, but when the GOP at the beginning or end of the clip does not include all 1 GOPs in the editing material stream, the editing is performed in the memory 22 as described above. Although all 1 GOPs in the material stream may be transferred, only necessary portions may be transferred. Also, for example, when the first GOP of the clip includes the two B pictures at the beginning of the MPEG Long GOP in the editing material stream, one of the B pictures is not included in order to decode these B pictures. It is necessary to supply the previous GOP to the decoder 23.

  A specific example of a GOP transfer range, a method for specifying a display output range, and a decoding process will be described with reference to FIGS. 15 to 18.

  Referring to FIG. 15, transient playback at ± 2 times speed is performed for a clip stream in which clip A, which is a part of stream A, and clip B, which is a part of stream B, are connected (reverse to the forward direction in a short interval). A first example of the GOP transfer and the operation of the decoder 23 in the case where the reproduction of the direction is continuously commanded will be described.

  Clip A includes a part of two GOPs, and in order to decode the frame included in clip A, it is a frame that is not included in clip A, but is included in these two GOPs. Multiple frames are required. Clip B includes a part of one GOP. In order to decode a frame included in clip B, a frame that is not included in clip B and that constitutes clip B is included. Multiple frames included in the previous GOP are required. That is, in order to decode a clip stream in which clip A and clip B are connected, four GOP data are required.

  In the first example, it is assumed that all GOPs necessary for playback of the clip stream are transferred. Then, half of the I picture and P picture included in the transferred GOP are preferentially decoded.

  The transfer GOP determination unit 52 determines the transfer order of GOPs when playing back in the forward direction from clip A to clip B based on the clip playback order and the arrangement of each GOP in the material stream. Based on this, GOP_IDs of these four GOPs are set as GOP_ID1 to GOP_ID4, and are set as GOPs to be transferred to the memory 18.

  The GOP transfer timing control unit 53 controls the GOP transfer timing. Specifically, the GOP data of GOP_ID1 to GOP_ID4 is transmitted at a predetermined timing prior to the display command so that the transferred GOP I picture and P picture are decoded and stored in the memory 22 in advance. Transferred.

  In each GOP of GOP_ID1 to GOP_ID4, after the data transfer is completed, a transfer completion command is transmitted to the command buffer 31 of the PCI bridge 17 at a predetermined timing.

  Then, the display command transmission unit 57 transmits a display command for each frame to the command buffer 31 of the PCI bridge 17 based on a user operation input.

  For example, as in the example of a picture output request shown in FIG. 15, when a playback instruction is issued in the forward direction from the beginning of clip A to B1 of Gop_ID 4, a playback instruction is issued in the reverse direction ( In the figure, when the playback output of the B3 picture of Gop_ID 2 is instructed next to the B1 picture of Gop_ID 4), at this point, it is predicted that the display instruction is issued next to the frame included in Gop_ID 2 The number of display frames up to P14 of 1 is only 5 frames. For this reason, if the information of the anchor frame of Gop_ID 1 is deleted from the owned anchor bank, the decoding required for display will not be in time before displaying P14 of Gop_ID 1, and the display screen may freeze. There is. Therefore, when transient playback of this clip stream is executed, it is desirable not to delete the decoded baseband image data of the retained anchor frame corresponding to Gop_ID 1 from the retained anchor bank. In consideration of such a case, it is preferable that 12 anchor frames are provided in the decoder 23.

  Further, in the clip stream shown in FIG. 15, the information of the B4 picture to the B13 picture of Gop_ID 2 is not necessary at all for the decoding of the frame in the clip, so that the transfer may not be performed. As a second example of the GOP transfer and the operation of the decoder 23, a case where only a frame requiring Gop_ID 2 is transferred will be described with reference to FIG.

  That is, the transfer GOP determination unit 52 selects only the range including the frames included in the clip and the frames necessary for decoding them in the GOP at the end of the clip, and sets only the portion to be transferred. Based on the clip playback order and the arrangement of each GOP in the material stream, the GOP_IDs of these four GOPs are set as GOP_ID1 to GOP_ID4, and are GOPs to be transferred to the memory 18. That is, in the case of FIG. 16, except that the number of frames transferred as Gop_ID 2 is different, basically, the GOP transfer timing control unit 53 performs the process of GOP as in the case described with reference to FIG. Transfer is controlled. Specifically, the GOP data of GOP_ID1 to GOP_ID4 is transferred at a predetermined timing prior to the display command so that the transferred GOP I picture and P picture are decoded in advance and stored in the memory 22. Is done.

  After the transfer of each GOP data of GOP_ID1 to GOP_ID4 is completed, a transfer completion command is transmitted to the command buffer 31 of the PCI bridge 17 at a predetermined timing.

  In the case of FIG. 16, even if a reproduction command similar to that described with reference to FIG. 15 is generated, compared to the case of FIG. 15, POP and I14 of GOP_ID 2 are not transferred, Even if the number is small, it is possible to prevent the display screen from freezing and perform transient reproduction. Here, it is preferable that ten anchor banks in the decoder 23 are provided.

  Further, the transfer may be executed in GOP units, and only the frames necessary for display may be decoded based on the output range designation command. As a third example of the GOP transfer and the operation of the decoder 23, a case where transfer is executed in units of GOP and only frames necessary for display are decoded by using an output range designation command will be described with reference to FIG. .

  The transfer GOP determination unit 52 sets GOP_IDs of these four GOPs as GOP_ID1 to GOP_ID4 based on the clip playback order and the arrangement of each GOP in the material stream as in the case described with reference to FIG. All of the frames included in these GOPs are GOPs that are transferred to the memory 18.

  Then, the output range information setting unit 54 sets the respective output ranges of GOP_ID1 to GOP_ID4 to be transferred. Here, the display output range of GOP_ID1 is 7-15, the display output range of GOP_ID2 is 1-4, the display output range of GOP_ID3 is 0-0, and the display output range of GOP_ID3 is 2-15.

  Similarly, the GOP transfer timing control unit 53 controls the GOP transfer timing. Specifically, the GOP data of GOP_ID1 to GOP_ID4 is transferred at a predetermined timing prior to the display command so that the transferred GOP I picture and P picture are decoded in advance and stored in the memory 22. Is done.

  Then, after the transfer of each GOP data of GOP_ID1 to GOP_ID4 is completed, an output range designation command is transmitted to the command buffer 31 of the PCI bridge 17 together with the transfer completion command at a predetermined timing.

  Since the CPU 20 controls the decoder 23 based on the output range designation command, only G2 of GOP_ID2 is decoded in the decoder 23 and held in the holding anchor bank. Further, the display output range of GOP_ID3 is 0-0, which is necessary only for displaying the first B1 of GOP_ID4, so it is only necessary that only P14 can be held in the possession anchor bank. Therefore, in this case, it is preferable that the anchor bank memory of the decoder 23 is provided for 8 frames.

  Further, as described with reference to FIGS. 16 and 17, only the necessary portion may be transferred and only the frame necessary for display may be decoded based on the output range designation command. As a fourth example of the GOP transfer and the operation of the decoder 23, a case where only a necessary part is set as a GOP transfer unit and only a frame necessary for display is decoded by using an output range designation command will be described with reference to FIG. Will be described.

  That is, the transfer GOP determination unit 52 selects only the frame necessary for decoding the frame included in the clip in the GOP at the end of the clip and sets only that portion to be transferred. The GOP_IDs of these four GOPs are set as GOP_ID1 to GOP_ID4 based on the arrangement of each GOP in the stream to be a GOP to be transferred to the memory 18.

  Then, the output range information setting unit 54 sets the respective output ranges of GOP_ID1 to GOP_ID4 to be transferred. Again, the display output range of GOP_ID1 is 7-15, the display output range of GOP_ID2 is 1-4, the display output range of GOP_ID3 is 0-0, and the display output range of GOP_ID3 is 2-15.

  The GOP transfer timing control unit 53 controls the GOP transfer timing. That is, the GOP data of GOP_ID 1 to GOP_ID 4 is transferred at a predetermined timing prior to the display command so that the transferred I picture and P picture of the GOP are decoded in advance and stored in the memory 22.

  After the transfer of each GOP data of GOP_ID1 to GOP_ID4 is completed, an output range designation command is transmitted to the command buffer 31 of the PCI bridge 17 together with the transfer completion command at a predetermined timing.

  Since the CPU 20 controls the decoder 23 based on the output range designation command, in the decoder 23, GOP_ID2 is coded only by I2 and held in the possessing anchor bank. Further, the display output range of GOP_ID3 is 0-0, which is necessary only for displaying the first B1 of GOP_ID4, so it is only necessary that only P14 can be held in the possession anchor bank. Therefore, also in the case of the fourth example, it is preferable that the anchor bank memories owned by the decoder 23 be provided for the number of frames.

  In the fourth example described with reference to FIG. 18, the display response is improved by reducing the amount of frame transfer compared to the first and third examples, and the first and second examples are improved. Compared to the example, by reducing the number of anchor frames that must be held, if the number of owned anchor bank memories is the same, the effect of improving the scrub playback response in a wider range can be obtained.

  With this method, clip playback can be realized even when scrub playback is executed, or when playback is performed by specifying a speed such as 1 × speed or 1.5 × speed, for example.

  Next, processing executed by the CPU 11 will be described with reference to the flowchart of FIG.

  In step S <b> 1, the operation input acquisition unit 51 of the CPU 11 inputs a clip setting, that is, which part of any encoded stream is cut out by the operation input unit (not shown) via the south bridge 15 and the north bridge 12. The input of the setting indicating how to connect the clip and the clip stream is received and supplied to the transfer GOP determination unit 52, the GOP transfer timing control unit 53, and the output range information setting unit 54.

  In step S2, the transfer GOP determination unit 52 determines each GOP included in the set clip and the GOP necessary for decoding the GOP ID based on the GOP transfer order when the clip stream is played in the forward direction. Set.

  In step S3, the operation input acquisition unit 51 receives a display start operation input executed by the user using the operation input unit (not shown) via the south bridge 15 and the north bridge 12, and receives the transfer GOP determination unit 52, To the GOP transfer timing control unit 53.

  In step S4, the transfer GOP determination unit 52 schedules the frame display order, and in step S5, designates a frame to be displayed and notifies the GOP transfer timing control unit 53 and the output range information setting unit 54 of the frame.

  In step S6, a display transfer unit determination process described later with reference to FIG. 21 is executed.

  In step S7, the GOP transfer timing control unit 53 determines whether there is a GOP currently being transferred.

  If it is determined in step S7 that there is no GOP currently being transferred, a forward transfer unit determination process described later with reference to FIG. 22 is executed in step S8.

  If it is determined in step S7 that there is a GOP currently being transferred, or after the process in step S8 is completed, a transfer completion transmission determination process described later with reference to FIGS. 23 to 26 is executed in step S9. .

  In step S10, the GOP transfer timing control unit 53 instructs the display command sending unit 57 to send the display command for the frame to be displayed designated in step S5. The display command transmission unit 57 transmits a display command to the command buffer 31 of the PCI bridge via the north bridge 12 and the PCI bus 14.

  In step S <b> 11, the transfer GOP determination unit 52 receives, for example, a change in display direction or speed or a change in displayed stream from the user based on a signal indicating the user operation input supplied from the operation input acquisition unit 51. It is determined whether or not an operation involving a change in the frame display order is input. If it is determined in step S11 that an operation involving a change in the frame display order has been input, the process returns to step S4, and the subsequent processes are repeated.

  If it is determined in step S <b> 11 that an operation involving a change in the frame display order has not been input, the transfer GOP determination unit 52 is a signal indicating the user's operation input supplied from the operation input acquisition unit 51 in step S <b> 12. Based on this, it is determined whether or not the display process is terminated. If it is determined in step S12 that the display process is not terminated, the process returns to step S5, and the subsequent processes are repeated. If it is determined in step S12 that the display process is to be terminated, the process is terminated.

  In this way, the CPU 11 determines the frame display order based on the user's operation input, and decodes the corresponding GOP I picture and P picture prior to the transmission of the display command. When the transfer unit and transfer timing are determined and the transfer is completed, a transfer completion command and an output range designation command are transmitted (transfer completion determination process in step S9, details will be described later), and then a display command is transmitted. When a display command is transmitted, there is a high possibility that the I picture and P picture of the corresponding GOP have already been decoded, and the display response to the display command is increased.

  Then, the CPU 20 controls the decoding process by the decoder 23 based on the command supplied from the CPU 11. Specifically, the CPU 20 inputs the compression encoded stream data to the memory 22, the data exchange timing between the memory 22 and the decoder 23, the decoding timing for each picture, and the decoded picture Output, that is, display timing is determined, and the PCI bridge 17, the memory 22, and the decoder 23 are controlled based on these timings.

  Next, the process of the CPU 20 that is executed in parallel with the process of the CPU 11 described with reference to FIG. 19 will be described with reference to the flowchart of FIG.

  In step S41, the command acquisition unit 71 of the CPU 20 refers to the command buffer 31 of the PCI bridge 17 via the control bus 19, and determines whether a GOP transfer completion command has been received. If it is determined in step S41 that a GOP transfer completion command has not been received, the process proceeds to step S45 described below.

  If it is determined in step S41 that the GOP transfer completion command has been received, in step S42, the command acquisition unit 71 indicates that the GOP transfer completion command has been received, indicating that the inter-memory transfer control unit 72 and the result sending unit 76 have received the GOP transfer completion command. Notify The inter-memory transfer control unit 72 confirms the completion of transfer of the GOP from the HDD 16 to the memory 18. The result sending unit 76 then returns a result for the GOP transfer completion command to the result buffer 32 of the PCI bridge 17 via the control bus 19.

  In step S43, the inter-memory transfer control unit 72 controls the transfer of GOP from the memory 18 to the memory 22. That is, the GOP transfer from the memory 18 to the memory 22 is not based on the timing when the GOP transfer to the memory 18 is completed by the inter-memory transfer control unit 72 but based on the timing when the GOP transfer completion command is received from the CPU 11. Is controlled.

  In step S44, the decoding schedule processing unit 73 schedules decoding so that the GOP anchor frame transferred to the memory 22 is preferentially decoded, and notifies the decoding control unit 74 of the schedule. The decode control unit 74 controls the decoding processing by the decoder 23 based on the decoding schedule by the decoding schedule processing unit 73.

  If it is determined in step S41 that a GOP transfer completion command has not been received, or after the processing in step S44 is completed, the command acquisition unit 71 passes the control bridge 19 via the PCI bus 17 in step S45. The command buffer 31 is referenced to determine whether a display command has been received. If it is determined in step S45 that no display command has been received, the process proceeds to step S48 described later.

  If it is determined in step S45 that a display command has been received, in step S46, the decode control unit 74 controls the decoder 23 and the memory 22 in order to output a picture to be displayed.

  Specifically, for example, when the frame for which display is instructed is an I picture or P picture that is a possessed anchor frame, it is detected whether or not baseband image data for which decoding has been completed is stored in the memory 22. When the baseband image data is stored in the memory 22, the baseband image data is output. Further, for example, when the frame commanded to be displayed is a B picture, it is detected whether or not the reference image data necessary for decoding the B picture is stored in the memory 22, and the reference image data is stored in the memory. If it is stored in 22, the output B picture is decoded using the reference image data.

  In step S47, the decode control unit 74 determines whether or not the display of the corresponding frame has ended. If it is determined in step S47 that the display of the corresponding frame has not ended, the process returns to step S46, and the subsequent processes are repeated.

  If it is determined in step S45 that the display command has not been received, or if it is determined in step S47 that the display of the corresponding frame has been completed, the command acquisition unit 71 determines in step S48 that the control bus 19 By referring to the command buffer 31 of the PCI bridge 17, it is determined whether or not the display process is terminated. If it is determined in step S48 that the display process has not been completed, the process returns to step S41, and the subsequent processes are repeated. If it is determined in step S48 that the display process has been completed, the process ends.

  By such processing, the CPU 20 controls transfer of GOP from the memory 18 to the memory 22 and decoding processing by the decoder 23 based on the control of the CPU 11. At that time, since at least a part of the GOP anchor frame transferred to the memory 22 is preferentially decoded, the response from the display command reception to the output of the decoded baseband image data is improved.

  Further, after acquiring a transfer completion command of a certain GOP, the CPU 20 controls the transfer of the data of the GOP from the memory 18 to the memory 22. That is, in the processing of the CPU 11, since the generation timing of the transfer completion command is later than the actual transfer timing of the GOP, for example, when the display start position is significantly changed in random playback, the memory 18 No data is transferred to the memory 20 in vain. Therefore, even when the data storage capacity of the memory 20 is smaller than that of the memory 18, it is possible to prevent the memory 20 from overflowing and overwriting of necessary data.

  Next, a display transfer unit determination process executed in step S6 of FIG. 19 will be described with reference to the flowchart of FIG.

  In step S71, the transfer GOP determination unit 52 of the CPU 11 determines whether or not the frame to be displayed is one of the first two B pictures of the GOP. If it is determined in step S71 that the frame to be displayed is not one of the first two B pictures of the GOP, the process proceeds to step S74 described later.

  If it is determined in step S71 that the frame to be displayed is one of the first two B pictures of the GOP, in step S72, the transfer GOP determination unit 52 determines that the B picture is forward. It is determined whether to refer to an existing GOP. If it is determined in step S72 that there is no reference to the previous GOP, such as a closed GOP or the first GOP of the stream, the process proceeds to step S74 described later.

  If it is determined in step S72 that there is a reference to the previous GOP, in step S73, the transfer GOP determination unit 52 has transferred the previous GOP, that is, the GOP including the forward reference image for this B picture. Determine whether or not. If it is determined in step S73 that the previous GOP has not been transferred, the process proceeds to step S76 described later.

  If it is determined in step S71 that the frame to be displayed is not one of the first two B pictures of the GOP, if it is determined in step S72 that there is no reference to the previous GOP, or step S73. In step S74, when it is determined that the previous GOP has been transferred, the transfer GOP determination unit 52 determines whether or not the GOP including the frame to be displayed has been transferred. If it is determined in step S74 that the GOP including the frame to be displayed has been transferred, the process returns to step S6 in FIG. 19 and proceeds to step S7.

  If it is determined in step S74 that the GOP including the frame to be displayed has not been transferred, the transfer GOP determination unit 52 determines in step S75 that the south bridge 15, the north bridge 12, the PCI bus 14, and the PCI bridge 17 The start of the transfer of the GOP including the frame to be displayed from the HDD 16 to the memory 18 is controlled via the, and the process returns to step S6 in FIG. 19 and proceeds to step S7.

  If it is determined in step S73 that the previous GOP has not been transferred, the transfer GOP determination unit 52 determines in step S76 that the GOP including the B picture, in other words, the GOP including the frame to be displayed is included. It is determined whether or not the transfer has been completed.

  If it is determined in step S73 that the GOP including the B picture has been transferred, the transfer GOP determining unit 52 determines in step S77 that the transfer GOP determination unit 52 has the south bridge 15, the north bridge 12, the PCI bus 14, and the PCI bridge 17. , The start of the transfer of the previous GOP from the HDD 16 to the memory 18 is controlled, and the process returns to step S6 in FIG. 19 and proceeds to step S7.

  If it is determined in step S73 that the GOP including the B picture has not been transferred, the transfer GOP determination unit 52 determines in step S78 that the south bridge 15, the north bridge 12, the PCI bus 14, and the PCI bridge 17 , The start of the transfer of I2B0B1 of the GOP displayed as the previous GOP from the HDD 16 to the memory 18 is controlled, and the process returns to step S6 in FIG. 19 and proceeds to step S7.

  By such processing, the displayed picture is one of the two B pictures at the head of the GOP, and the GOP including the B picture and the previous GOP (that is, the displayed B picture). If no GOP that includes a reference image frame necessary for decoding is transferred, I2B0B1 of the GOP displayed as the previous GOP is transferred. Therefore, even when the currently executed reproduction process is a high-speed reproduction process and no other frame of the GOP including the B picture is displayed, useless data is not transferred, and the high-speed reproduction process is performed. Instead, since the other frame of the GOP including the B picture is displayed, even if it is necessary to transfer the GOP including the B picture, the redundancy of the transfer data Less is.

  Next, with reference to the flowchart of FIG. 22, the forward transfer unit determination process executed in step S8 of FIG. 19 will be described.

  In step S101, the GOP transfer timing control unit 53 determines whether or not the displayed frame is a frame included in the same GOP as the previously displayed frame. If it is determined in step S101 that the displayed frame is a frame included in the same GOP as the previously displayed frame, the process returns to step S8 in FIG. 19 and proceeds to step S9.

  When it is determined in step S101 that the frame to be displayed is not a frame included in the same GOP as the previously displayed frame, that is, when it is determined that the frame is a transition of the GOP in the frame to be displayed. In step S102, the GOP transfer timing control unit 53 determines whether or not the displayed frame is a frame included in the GOP that is one behind the GOP that includes the previously displayed frame. That is, it is determined whether or not it is a change of GOP in forward reproduction. If it is determined in step S102 that the frame to be displayed is not a frame included in the GOP that is one behind the GOP in which the previously displayed frame was included, the process proceeds to step S106 described later. Proceed to

  If it is determined in step S102 that the frame to be displayed is a frame included in the GOP that is one behind the GOP in which the previously displayed frame was included, in step 103, the GOP transfer timing is determined. The control unit 53 determines whether or not the number of frames in the display range included in the GOP immediately after the GOP including the frame to be displayed (already started transfer) is 6 frames or more.

  Here, the determination is performed using 6 frames as a threshold value, but the number of frames varies depending on the reproduction capability required by the apparatus and the memory capacity of the memory 18. For example, when the memory capacity of the memory 18 is small, the memory 18 may overflow if the transfer is started too early. However, when the memory capacity of the memory 18 is sufficient, the threshold value is determined based on how many times the playback function of this device has in the forward and reverse directions. For example, when a playback function of about double speed is required in the forward direction and the reverse direction, a sufficient number of frames are transferred in advance so that playback does not freeze by setting 6 frames as a threshold value.

  If it is determined in step 103 that the number of frames in the display range included in the next GOP is 6 frames or more, in step S104, the GOP transfer timing control unit 53 includes, for example, a frame to be displayed. The priority is lower than the GOP or command that is being transferred, and the transfer of the next GOP is started. The processing returns to step S8 in FIG. 19 and proceeds to step S9.

  That is, in comparison with the process of transmitting a command such as a display command or the process of transferring a GOP that is likely to be reproduced next to the GOP including the currently reproduced frame, the data is preceded at the change of the GOP. The transfer process is not urgent because it is a process of transferring data that will be used next. Therefore, by assigning priorities, it is possible to improve the efficiency of data transfer without degrading the response of processing necessary for displaying a picture such as command transmission.

  If it is determined in step 103 that the number of frames in the display range included in the next GOP is 6 frames or less, in step S105, the GOP transfer timing control unit 53 includes, for example, a frame to be displayed. Lowering the priority over the GOP or command that is being transferred, the transfer of 2 GOPs of the next GOP and the next GOP is started, and the process returns to step S8 in FIG. Proceed to

  If it is determined in step S102 that the displayed frame is not a frame included in the GOP that is one behind the GOP in which the previously displayed frame was included, in step S106, the GOP transfer timing is determined. The control unit 53 determines whether or not the displayed frame is a frame included in the GOP immediately preceding the GOP in which the previously displayed frame was included, that is, the GOP in reverse playback. It is determined whether or not it is a turning point. In step S106, if it is determined that the displayed frame is not a frame included in the GOP immediately preceding the GOP in which the previously displayed frame was included, it is skipped without displaying more than 1 GOP. Since the high-speed playback is performed or the playback start position is changed by scrub playback, the process returns to step S8 in FIG. 19 and proceeds to step S9.

  If it is determined in step S106 that the displayed frame is a frame included in the GOP immediately preceding the GOP in which the previously displayed frame was included, in step 107, the GOP transfer timing is determined. The control unit 53 determines whether or not the number of frames in the display range included in the GOP immediately before the GOP including the frame to be displayed (already started transfer) is 6 frames or more.

  If it is determined in step 107 that the number of frames in the display range included in the previous GOP is 6 frames or more, in step S108, the GOP transfer timing control unit 53 includes, for example, a frame to be displayed. The priority is set lower than that of the GOP or command being started, and the transfer of the previous GOP is started, and the process returns to step S8 in FIG. 19 and proceeds to step S9.

  If it is determined in step 107 that the number of frames in the display range included in the previous GOP is 6 frames or less, in step S109, the GOP transfer timing control unit 53 includes, for example, a frame to be displayed. The priority is lowered than the GOP or command being used, and the transfer for 2 GOPs of the previous GOP and the previous GOP is started, and the process returns to step S8 in FIG. Proceed to

  By such processing, the transfer of the GOP that is predicted to be displayed next can be started at the timing when the GOP transition frame is displayed, and the number of display frames included in the GOP When the number of frames is small, another 1 GOP transfer is started, so that it is possible to prevent the display response from deteriorating due to the frame data not being transferred in time.

  Next, the transfer completion transmission determination process executed in step S9 of FIG. 19 will be described with reference to the flowcharts of FIGS.

  In step S131, the GOP transfer timing control unit 53 determines whether there is a GOP for which transfer has been completed and transfer completion has not been transmitted. If it is determined in step S131 that there is no GOP that has been transferred and has not transmitted transfer completion, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S131 that there is a GOP for which transfer has been completed and transfer completion has not been transmitted, in step S132, the GOP transfer timing control unit 53 determines the transfer GOP determined by the transfer GOP determination unit 52. Information and the output range set by the output range information setting unit 54, the GOP is a GOP next to the frame being displayed, and whether or not the display range is less than 6 frames. to decide.

  If it is determined in step S132 that the GOP is not the GOP adjacent to the frame being displayed or the display range is not less than 6 frames, the process proceeds to step S136 described later.

  If it is determined in step S132 that the GOP is the GOP next to the frame being displayed and the display range is less than 6 frames, the transfer completion command sending unit 56 in step S133 It is determined whether or not the transfer completion command has been transmitted. If it is determined in step S133 that the transfer completion command for the GOP has been transmitted, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S133 that the transfer completion command for the GOP has not been transmitted, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed in step S134.

  In step S135, the output range information setting unit 54 transmits the output range designation command of the GOP to the command buffer 31 of the PCI bridge 17, and the transfer completion command sending unit 56 determines the completion of transfer of the GOP of the PCI bridge 17. The data is transmitted to the command buffer 31, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S132 that the GOP is not the GOP adjacent to the frame being displayed or the display range is not less than 6 frames, the GOP transfer timing control unit 53 displays the frame to be displayed in step S136. Determines whether the frame is included in the same GOP as the previously displayed frame. If it is determined in step S136 that the frame to be displayed is not included in the same GOP as the previously displayed frame, the process proceeds to step S151 described later.

  If it is determined in step S136 that the displayed frame is a frame included in the same GOP as the previously displayed frame, in step S137, the GOP transfer timing control unit 53 determines that the displayed frame is Then, it is determined whether or not the frame is positioned behind the previously displayed frame. If it is determined in step S137 that the displayed frame is located behind the previously displayed frame in time, that is, if the playback direction is determined to be the forward direction, the process is described later. The process proceeds to S156.

  If it is determined in step S137 that the frame to be displayed is not located behind the previously displayed frame, that is, the playback direction is the reverse direction, the GOP transfer is performed in step S138. The timing control unit 53 determines whether or not the displayed frame is within 5 frames from the head of the GOP. If it is determined in step S138 that the frame to be displayed is not within 5 frames from the head of the GOP, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S138 that the frame to be displayed is a frame within 5 frames from the head of the GOP, in step S139, the GOP transfer timing control unit 53 selects one of the GOPs including the displayed frame. Consider whether the data of the previous GOP is being transferred.

  If it is determined in step S139 that the previous GOP data is being transferred, in step S140, the GOP transfer timing control unit 53 displays a frame display command included in the previous GOP being transferred. Since there is not much time left until the is issued, the priority of data transfer is increased, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S139 that the previous GOP data is not being transferred, in step S141, the GOP transfer timing control unit 53 determines whether or not the previous GOP data has been transferred. to decide.

  If it is determined in step S141 that the data of the previous GOP has not been transferred, the GOP transfer timing control unit 53 transfers the previous GOP with a higher priority in step S142. The process proceeds to step S146 described later.

  If it is determined in step S141 that the data of the previous GOP has been transferred, in step S143, the transfer completion command sending unit 56 has transmitted the transfer completion command for the previous GOP. Judge whether or not.

  If it is determined in step S143 that the transfer completion command for the previous GOP has not been transmitted, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed in step S144.

  In step S145, the output range information setting unit 54 transmits the previous GOP output range designation command to the command buffer 31 of the PCI bridge 17, and the transfer completion command sending unit 56 transfers the previous GOP. The completion is transmitted to the command buffer 31 of the PCI bridge 17.

  After the process of step S142 is completed, if it is determined in step S143 that the transfer completion command for the previous GOP has been transmitted, or after the process of step S145 is completed, the GOP transfer timing control is performed in step S146. The unit 53 determines whether or not the display range of the previous GOP is less than 6 frames based on the output range set by the output range information setting unit 54.

  If it is determined in step S146 that the display range of the previous GOP is not less than 6 frames, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  When it is determined in step S146 that the display range of the previous GOP is less than 6 frames, in step S147, the GOP transfer timing control unit 53 determines whether or not the data of the previous GOP has been transferred. Judging. If it is determined in step S147 that the data of the previous GOP has not been transferred, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S147 that the data of the second previous GOP has been transferred, in step S148, the transfer completion command sending unit 56 has transmitted the transfer completion command for the second previous GOP. Judge whether or not. If it is determined in step S148 that the transfer completion command for the previous GOP has been transmitted, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S148 that the transfer completion command for the previous GOP has not been transmitted, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed in step S149.

  In step S150, the output range information setting unit 54 transmits the output range designation command of the second previous GOP to the command buffer 31 of the PCI bridge 17, and the transfer completion command sending unit 56 transfers the second previous GOP. The completion is transmitted to the command buffer 31 of the PCI bridge 17, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S136 that the frame to be displayed is not included in the same GOP as the previously displayed frame, in step S151, the transfer completion command sending unit 56 determines that the frame to be displayed is It is determined whether or not a transfer completion of a GOP has been transmitted. If it is determined in step S151 that the GOP transfer completion with a frame to be displayed has been transmitted, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S151 that the transfer completion of the GOP with the frame to be displayed has not been transmitted, the GOP transfer timing control unit 53 determines whether or not the GOP with the frame to be displayed has been transferred in step S152. Judging.

  If it is determined in step S152 that the GOP with the frame to be displayed has not been transferred, the GOP transfer timing control unit 53 increases the priority in step S153 and completes the transfer of the GOP with the frame to be displayed. Wait for.

  If it is determined in step S152 that a GOP with a frame to be displayed has been transferred, or after the processing of step S153, that is, the transfer of the displayed frame is completed, but the transfer completion command is still When not transmitted, in step S154, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed.

  In step S155, the transfer completion command sending unit 56 transmits the transfer completion of the GOP with the frame to be displayed together with the output range designation command, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S137 that the frame to be displayed is located behind the previously displayed frame, that is, the playback direction is the forward direction, in step S156, the GOP transfer is performed. The timing controller 53 determines whether the displayed frame is a frame within 5 frames from the end of the GOP. If it is determined in step S156 that the displayed frame is not within 5 frames from the end of the GOP, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S156 that the displayed frame is within 5 frames from the end of the GOP, in step S157, the GOP transfer timing control unit 53 is transferring the data of the next GOP. Judge whether there is.

  If it is determined in step S157 that the next GOP data is being transferred, in step S158, the GOP transfer timing control unit 53 displays a frame display command included in the next GOP being transferred. Since there is not much time left until the is issued, the priority of data transfer is increased, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S157 that the next GOP data is not being transferred, in step S159, the GOP transfer timing control unit 53 determines whether or not the next GOP data has been transferred. to decide.

  If it is determined in step S159 that the data of the next GOP has not been transferred, the GOP transfer timing control unit 53 transfers the next GOP with a higher priority in step S160. The process proceeds to step S164 described later.

  If it is determined in step S159 that the data of the next GOP has been transferred, in step S161, the transfer completion command sending unit 56 has transmitted the transfer completion command for the next GOP. Judge whether or not.

  If it is determined in step S161 that the transfer completion command for the next GOP has not been transmitted, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed in step S162.

  In step S163, the output range information setting unit 54 transmits the output range designation command of the next GOP to the command buffer 31 of the PCI bridge 17, and the transfer completion command sending unit 56 completes the transfer of the next GOP. Is transmitted to the command buffer 31 of the PCI bridge 17.

  After the process of step S160 is completed, if it is determined in step S161 that the transfer completion command for the next GOP has been transmitted, or after the process of step S163 is completed, the GOP transfer timing control is performed in step S164. The unit 53 determines whether or not the display range of the next GOP is less than 6 frames based on the output range set by the output range information setting unit 54.

  If it is determined in step S164 that the display range of the next GOP is not less than 6 frames, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S164 that the display range of the previous GOP is less than 6 frames, in step S165, the GOP transfer timing control unit 53 determines whether or not the data of the second GOP has been transferred. Judging. If it is determined in step S165 that the data of the second GOP has not been transferred, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S165 that the data of the second succeeding GOP has been transferred, in step S166, the transfer completion command sending unit 56 has transmitted the transfer completion command for the second succeeding GOP. Judge whether or not. In step S166, when it is determined that the transfer completion command for the next GOP has been transmitted, the process returns to step S9 in FIG. 19 and proceeds to step S10.

  If it is determined in step S166 that the transfer completion command for the second GOP has not been transmitted, an output range designation command setting process, which will be described later with reference to FIG. 28, is executed in step S167.

  In step S168, the output range information setting unit 54 transmits the output range designation command of the second succeeding GOP to the command buffer 31 of the PCI bridge 17, and the transfer completion command sending unit 56 transfers the second succeeding GOP. The completion is transmitted to the command buffer 31 of the PCI bridge 17, and the process returns to step S9 in FIG. 19 and proceeds to step S10.

  By such processing, when the display in the forward direction is within 5 frames from the back of the GOP, in the case of the display in the reverse direction, the displayed frame is 5 frames from the front of the GOP. When the transfer is not completed, it is determined whether or not the transfer of the GOP predicted to be displayed next is completed after the transfer is started first at the change of the GOP in the displayed frame. When the transfer priority becomes high and the transfer is completed, the transfer completion command is transmitted together with the output range designation command.

  Thereby, for example, when the display start position is significantly changed in random reproduction, data is not transferred from the memory 18 to the memory 20 unnecessarily. Therefore, even when the data storage capacity of the memory 20 is smaller than that of the memory 18, it is possible to prevent the memory 20 from overflowing and overwriting of necessary data.

  Further, when the transfer of the GOP including the displayed frame is not completed, the transfer priority of the GOP becomes high.

  Referring to FIG. 27, a clip file A is selected from a P8 picture of the GOP with the first stream to a P8 picture of the next GOP as the clip file A, and P14 of the GOP with the second stream is selected as the clip file B. Timing control example such as command transmission when transient playback is executed in clip playback in which clip file A and clip file B are played back continuously from the picture to the P14 picture of the next GOP explain.

  For example, as shown in FIG. 27A, when the display frame shifts in the forward direction and the displayed frame shifts from the first GOP of the clip file A to the second GOP, the next frame further follows. It is determined whether the GOP is being transferred or has been transferred, and if it is not being transferred or transferred yet, transfer is commanded.

  Then, as shown in FIG. 27B, the next GOP, that is, the first GOP of the clip file B is transferred. Since the display range of this GOP is only P14 pictures and is less than 6 frames, the next GOP, that is, the second GOP of the clip file B is also transferred following this GOP.

  Then, as shown in FIG. 27C, when the transfer of the first GOP of the clip file B is completed during the display of the frame included in the second GOP of the clip file A, Since it is the GOP next to the GOP including the currently displayed frame and the display range is less than 6 frames, the transfer completion command is immediately transmitted. Then, it is assumed that the display reproduction direction is reversed from the state of FIG. 27C and reverse reproduction is performed.

  When transfer of the second GOP of the clip file B is completed, reverse playback is being performed as shown in FIG. 27D, and a frame included in the second GOP of the clip file A is being displayed. Since the transfer completed GOP is not the GOP next to the GOP including the currently displayed frame, the transfer completion command is not transmitted yet. Then, it is assumed that the display reproduction direction is reversed from the state of FIG. 27D and the normal direction reproduction is performed again.

  Then, as shown in FIG. 27E, in forward reproduction, the displayed frame is within 5 frames from the end of the GOP including the displayed frame, and the display range of the next GOP is within 6 frames. If the condition that the transfer of the second GOP is completed is satisfied, a transfer completion command for the second GOP of the clip file B is transmitted.

  Next, referring to the flowchart in FIG. 28, the output range executed in step S134 in FIG. 23, step S144 and step S149 in FIG. 24, step S154 in FIG. 25, and step S162 and step S167 in FIG. The specified command setting process will be described.

  In step S181, the output range information setting unit 54 is a GOP having a frame used as a reference image for decoding any clip, although the GOP for setting the output range designation command is not included in the clip. Determine whether or not.

  When it is determined in step S181 that the GOP has a frame that is not included in the clip but is used as a reference image for decoding any clip, in step S182, the output range information setting unit 54 The output range designation command is set to 0-0, and the process returns to the transfer completion transmission determination process described with reference to FIGS. 23 to 26, that is, returns to step S134 in FIG. 23 and proceeds to step S135. Returning to step S144 of 24 and proceeding to step S145, returning to step S149 and proceeding to step S150, returning to step S154 of FIG. 25 and proceeding to step S155, or returning to step S162 of FIG. 26 and proceeding to step S163 Alternatively, the process returns to step S167 and proceeds to step S168 (the output of FIG. 28). In the description of the enclosed specification command setting process, hereinafter the same).

  If it is determined in step S181 that the GOP is included in the clip, in step S183, the output range information setting unit 54 determines whether the GOP for setting the output range designation command is the first GOP of the clip. Determine whether.

  If it is determined in step S183 that the GOP is the head GOP of the clip, in step S184, the output range information setting unit 54 sets an output range designation command based on the clip setting (for example, 7-15, 9). -15), and the process returns to the transfer completion transmission determination process described with reference to FIGS.

  If it is determined in step S183 that it is not the first GOP of the clip, in step S185, the output range information setting unit 54 determines whether or not the GOP for setting the output range designation command is the last GOP of the clip. Judging.

  If it is determined in step S185 that it is the last GOP of the clip, in step S186, the output range information setting unit 54 sets an output range designation command based on the setting of the clip (for example, 0-4, Then, the process returns to the transfer completion transmission determination process described with reference to FIGS.

  If it is determined in step S185 that the GOP is not the last GOP of the clip, in step S187, the output range information setting unit 54 sets an output range designation command assuming that there is a possibility of output in the entire range of the GOP. Then, the process returns to the transfer completion transmission determination process described with reference to FIGS.

  As a result of such processing, the output range designation command is set and transmitted. For example, the anchor frame of the GOP that is not included in the clip but is transferred for use as a reference image is a possessed anchor frame. In addition, overwriting can be performed in the owned anchor banks, and the number of GOPs that can be processed with the same number of owned anchor banks can be increased.

  By performing the processing as described above, it is possible to easily and quickly control scrub playback and forward / reverse frame-by-frame playback during clip playback.

  That is, determination of the transfer unit of GOP transfer and control of transfer timing are not complicated, so that control is simplified and data transfer redundancy such as overlapping data is reduced.

  Here, the case where MPEG is used as the codec method is described as an example, but it goes without saying that the present invention can also be applied to the case where codec processing involving frame correlation is performed. For example, AVC (Advanced Video Coding) / H. The present invention is applicable to H.264.

  Note that the AVC / H.264 B picture does not necessarily use the forward and backward bi-directional reference images. Even if prediction is performed using two reference images from the past, Although prediction may be performed using a single reference image, the present invention can be applied in consideration of such a case.

  In the above description, the CPU 11 and the CPU 20 have been described as transmitting / receiving control information via the command buffer 31 and the result buffer 32 of the PCI bridge 17, and sharing the control information. These processes may be executed using a single CPU.

  In that case, as shown in the functional block diagram of FIG. 29, the functions of the CPU are the operation input acquisition unit 51, transfer GOP determination unit 52, GOP transfer timing control unit 53, and output range described with reference to FIG. The information setting unit 54, the register 55, the display command sending unit 57, the inter-memory transfer control unit 72, the decode schedule processing unit 73, the decode control unit 74, and the register 75 are basically the same.

  The series of processes described above can also be executed by software. The software is a computer in which the program constituting the software is incorporated in dedicated hardware, or various functions can be executed by installing various programs, for example, a general-purpose personal computer For example, it is installed from a recording medium. In this case, the processing described above is executed by a personal computer 201 as shown in FIG.

  In FIG. 30, a CPU (Central Processing Unit) 211 performs various processes according to a program stored in a ROM (Read Only Memory) 212 or a program loaded from a storage unit 218 to a RAM (Random Access Memory) 213. Execute. The RAM 213 also appropriately stores data necessary for the CPU 211 to execute various processes.

  The CPU 211, ROM 212, and RAM 213 are connected to each other via an internal bus 214. An input / output interface 215 is also connected to the internal bus 214.

  The input / output interface 215 includes an input unit 216 including a keyboard and a mouse, a display including a CRT and an LCD, an output unit 217 including a speaker, a storage unit 218 including a hard disk, a modem, a terminal adapter, and the like A communication unit 219 is connected. The communication unit 219 performs communication processing via various networks including a telephone line and CATV.

  A drive 220 is connected to the input / output interface 215 as necessary, and a magnetic disk 231 (including a flexible disk), an optical disk 232 (CD-ROM (Compact Disk-Read Only Memory), DVD (Digital Versatile Disk)) A magneto-optical disk 233 (including MD (Mini-Disk) (trademark)), or a semiconductor memory 234 or the like is appropriately mounted, and a computer program read therefrom is stored in the storage unit 218 as necessary. Installed.

  When a series of processing is executed by software, a program constituting the software is installed from a network or a recording medium.

  As shown in FIG. 30, this recording medium is distributed to provide a program to the user separately from the computer, and the magnetic disk 231, the optical disk 232, the magneto-optical disk 233 on which the program is recorded, or a semiconductor It is configured by a package medium including a memory 234 and the like.

  Further, in the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but may be performed in parallel or It also includes processes that are executed individually.

  Furthermore, in the above-described embodiment, the case where the compressed stream data is stored in the HDD 16 is described. However, the present invention is not limited to this, and for example, an optical disk, a magneto-optical disk, a semiconductor memory, a magnetic disk, etc. The present invention can also be applied to the case of decoding stream data recorded on various recording media.

  In the present specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is a figure for demonstrating the conventional edit process. It is a block diagram which shows the structure of a reproducing | regenerating apparatus. It is a figure for demonstrating clip reproduction | regeneration. It is a figure for demonstrating a reference image. It is a functional block diagram for demonstrating the function of CPU. It is a block diagram which shows the structure of a decoder. It is a figure for demonstrating the header information of GOP. It is a figure for demonstrating a stream buffer GOP queue. It is a figure for demonstrating a holding anchor frame and a non-holding anchor frame. It is a figure for demonstrating the stream buffer GOP queue. It is a figure for demonstrating a bank structure. It is a figure for demonstrating a GOP holding | maintenance anchor queue. It is a figure for demonstrating management of a possession anchor bank. It is a figure for demonstrating management of a possession anchor bank. It is a figure for demonstrating the transfer range and decoding process of GOP. It is a figure for demonstrating the transfer range and decoding process of GOP. It is a figure for demonstrating the transfer range and decoding process of GOP. It is a figure for demonstrating the transfer range and decoding process of GOP. It is a flowchart for demonstrating the process of CPU11. It is a flowchart for demonstrating the process of CPU20. It is a flowchart for demonstrating the transfer unit determination process for a display. It is a flowchart for demonstrating the transfer unit determination process for advance. It is a flowchart for demonstrating the transfer completion transmission determination process. It is a flowchart for demonstrating the transfer completion transmission determination process. It is a flowchart for demonstrating the transfer completion transmission determination process. It is a flowchart for demonstrating the transfer completion transmission determination process. It is a figure for demonstrating the specific example of a process. It is a flowchart for demonstrating an output range designation | designated command setting process. It is a functional block diagram for demonstrating the function of CPU. It is a block diagram which shows the structure of a personal computer.

Explanation of symbols

  1 playback device, 11 CPU, 16 HDD, 18 memory, 20 CPU, 22 memory, 23 decoder, 51 operation input acquisition unit, 52 transfer GOP determination unit, 53 GOP transfer timing control unit 53 output range information setting unit, 56 transfer completion Command sending unit, 72 Memory transfer control unit, 73 Decode schedule processing unit, 74 Decode control unit, 153 Decode controller

Claims (9)

In the information processing apparatus that controls to output in a state where the first encoded stream and the second encoded stream are connected,
An operation input acquisition means for acquiring an operation input indicating a range to be reproduced of the first encoded stream and the second encoded stream;
Decoding means for decoding the encoded stream stored in the storage means for storing the encoded stream to generate image data;
The first encoded stream and the second encoded stream in the range corresponding to the operation input acquired by the operation input acquisition means, and the first encoded stream in the range corresponding to the operation input and an encoded stream necessary for decoding the second encoded stream, and controls so as to transfer to said storing means, said storing said first coded stream and the second encoded stream A picture unit of the image data whose output is instructed by command means for determining a transfer unit to be transferred to the means and instructing timing for outputting the image data decoded by the decoding means is a first GOP including the picture. When included in a B picture decoded with reference to a picture included in a second GOP different from A B picture decoded with reference to a picture included in the second GOP of one GOP, a reference picture necessary for decoding the B picture, and the second GOP, Transfer control means for determining a transfer unit to be transferred to the storage means ;
Predicting a command output timing of the image data instructed by said instruction means, ahead of the command output timing of the image data, and said first encoded stream and the second encoded stream Transfer timing control means for controlling transfer timing so as to transfer to the storage means;
Of the first encoded stream and the second encoded stream stored in the storage unit, the decoding unit is configured to preferentially decode a reference picture to be referred to when decoding a decoding target picture. An information processing apparatus comprising: a decoding control means for controlling decoding of. The transfer control unit controls the first encoded stream and the second encoded stream to be transferred to the storage unit as transfer data of a predetermined transfer unit;
The transfer timing control means transfers the next transfer data to the storage means when the number of pictures to be displayed is less than or equal to a predetermined number of pictures among the transfer data controlled to be transferred to the storage means. The information processing apparatus according to claim 1. The first encoded stream and the second encoded stream have a GOP structure including a B picture,
The transfer control means, when the picture of the image data whose output has been instructed by the instruction means has not been transferred to the holding means in the first GOP and the second GOP, Among the GOPs, the B picture decoded with reference to the picture included in the second GOP, the reference picture necessary for decoding the B picture, and the second GOP, Determine as a transfer unit to be transferred to the storage means
The information processing apparatus according to claim 1 . The system further comprises control information generating means for generating control information indicating a range for reproducing the first encoded stream and the second encoded stream in accordance with the operation input acquired by the operation input acquiring means. The information processing apparatus according to 1. The first encoded stream and the second encoded stream have a GOP structure,
The transfer control means controls to transfer the first encoded stream and the second encoded stream in GOP units.
The information processing apparatus according to claim 4 . The information processing apparatus according to claim 1, wherein the first encoded stream and the second encoded stream are streams encoded according to an MPEG standard. In the information processing method of the information processing apparatus that controls to output the first encoded stream and the second encoded stream in a connected state,
Obtaining an operation input indicating a playback range of the first encoded stream and the second encoded stream;
The first encoded stream and the second encoded stream in a range corresponding to the acquired operation input, and the first encoded stream and the second code in a range corresponding to the operation input the coded stream necessary for decoding the stream, and controls so as to transfer to the storage means for storing the coded stream, the first encoded stream and the second of said storage means the coded stream A picture unit of the image data for which the timing for outputting the image data obtained by decoding the encoded stream stored in the storage means is output is determined. When the first picture is included in a B picture decoded with reference to a picture contained in a second GOP different from the GOP, the first Of the GOP, the B picture decoded with reference to the picture included in the second GOP, the reference picture necessary for decoding the B picture, and the second GOP are stored. Determine the transfer unit to be transferred to the means ,
Predicting the output timing command of the image data to which the timing for outputting the decoded image data of the encoded stream stored in the storage means is predicted, and precedes the output timing command of the image data. A transfer timing is controlled so as to transfer the first encoded stream and the second encoded stream to the storage means;
A step of controlling to preferentially decode a reference picture to be referred to when decoding a picture to be decoded out of the first encoded stream and the second encoded stream stored in the storage means; Information processing method including. A program for causing a computer to execute a process of controlling to output a first encoded stream and a second encoded stream in a connected state,
Obtaining an operation input indicating a playback range of the first encoded stream and the second encoded stream;
The first encoded stream and the second encoded stream in a range corresponding to the acquired operation input, and the first encoded stream and the second code in a range corresponding to the operation input the coded stream necessary for decoding the stream, and controls so as to transfer to the storage means for storing the coded stream, the first encoded stream and the second of said storage means the coded stream A picture unit of the image data for which the timing for outputting the image data obtained by decoding the encoded stream stored in the storage means is output is determined. When the first picture is included in a B picture decoded with reference to a picture contained in a second GOP different from the GOP, the first Of the GOP, the B picture decoded with reference to the picture included in the second GOP, the reference picture necessary for decoding the B picture, and the second GOP are stored. Determine the transfer unit to be transferred to the means ,
Predicting the output timing command of the image data to which the timing for outputting the decoded image data of the encoded stream stored in the storage means is predicted, and precedes the output timing command of the image data. A transfer timing is controlled so as to transfer the first encoded stream and the second encoded stream to the storage means;
A step of controlling to preferentially decode a reference picture to be referred to when decoding a picture to be decoded out of the first encoded stream and the second encoded stream stored in the storage means; A program that causes a computer to execute the processing that includes it. A recording medium on which the program according to claim 8 is recorded.

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